There are those who would have us believe that the traditional V8 scene is dying.

Such doomsday prophets claim that modern four and six-cylinder cars will soon take over, along with equally modern quad-cam EFI V8 engines from Japan, America and Europe.

Wonder where that leaves Mark’s 1977 HZ Sandman ute then ?

No, Mark hasn’t got a sequentially injected late model computer controlled powerplant under that scoop and bonnet, but there’s still plenty of late model technology in there.

How’s this for a recipe…

First fill an engine with the very best hardware, then add the latest carburettor technology and top it all off with advanced supercharger design.

All that on top of an OZNOS nitrous kit, and you get an estimated power output of 600 ponies at the engine!

Expect the unexpected
Mark and his wife Katherine run their own automotive repair and performance shop in the genteel country town of York, which does have strong automotive connections with its renowned vintage car museum, but it’s perhaps not the place you’d expect to find a thriving street performance scene.

Nonetheless, word has spread fast about Mark’s Workshop (that’s actually the name of the business - simple, eh !) and in addition to the Sandman ute, Mark has a Vortech Supercharged Series I VT GTS Commodore.

In fact, Mark was amongst the first in WA to supercharge a Series I VT and he has since blown numerous other Commodores in the York area.

But back to the Sandman ute, which Mark has owned for 11 years.

The definitive Aussie legend was in good condition when Mark bought it, and a warm 308 provided initial excitement in those early days.

Over the years however, one thing led to another and the end result is an absolute pearler.

We’ll come back to the mechanicals in a moment, because the first thing you notice about Mark’s Sandman is how straight and immaculate the body is.

John Del Bianco in Perth performed what were really minor body repairs, before applying the 2-pak ‘Caribean’ Protec paintwork. The pin striping Mark designed himself, before it was applied by WW Auto Graphics.

In real life, the paintwork is deep and full of lustre, combining beautifully with those golden 15" Symmons rims.

The front wheels are 8-inchers wrapped in 255/45 ZR15 Yokohama street racing rubber, while the 9-inchers at the rear wear 265 50HR 15 Yokohama 352 rubber.

Not so obvious are the DBA cross drilled and slotted rotors gripped by PBR WB Statesman spec’ callipers on all four corners. The anchors are also backed up by fully legal (read flexible) stainless steel lines.

Suspension duties meanwhile come down to Lovells springs up front with heavy duty Pedders shocks, while the same shocks have been added to the rear.

The springs at the back haven’t been touched since the car left the factory, but there’s now a central ladder bar arrangement which has been fitted up to a 4-pin Salisbury LSD diff’.

The business end of things
Alright, so now let’s head back up front and dive under that bonnet.

To tell the complete truth, Mark had only just completed the final stages of his ultimate engine build when we arrived in York for the photo shoot.

Since that original warm 308, a few combos have been tried with and without the Whipple blower.

In fact - though it’s probably not something Mark would like publicised - the first attempt at supercharging resulted in a 17psi Avgas monster that destroyed rods, pistons and a block !!

Mark admits that the big mistake on that occasion was incorrect fuel delivery, but with increased knowledge and a Dynamic Test Systems dyno (the only one in WA) in the workshop, those problems are a thing of the past.

The engine now is still a 308, but the block is a genuine four-bolt mains VN Group A item which Mark acquired fully prepared and bored 30 thou’.

An ex Holden Racing SP crank, described as ‘the pick of the bunch’ lives in the deep end and runs eight Yella Terra Super rods.

The slugs are Speed Pro forged items wrapped with JE premium rings.

Not surprisingly either, the block has been O-ringed and uses copper head gaskets to mate up to those pre-smog HQ heads.

Often overlooked – and very tricky
Back to the other end of the block for just a moment, and an item that most don’t give any consideration to.

The sump on this Sandman is a high energy ‘Kick Out’ unit with a complex internal trap door and windage tray arrangement, which has actually been proven to produce 15hp all by itself in the Group A arena.

Up to the heads again, where the well known Mick Marriott performed a flow job good enough for 440Hp. The heads were then filled with some radical valve gear, including oversize 1-piece stainless Rev valves (2.002" inlet / 1.640" exhaust), Crow double springs, Crow retainers and Crane roller rockers.

The connection between all of this and the Crow roller cam is Crane roller lifters and Crane chrome moly pushrods.

Meanwhile, that cam offers 270 degrees of duration at 50 thou’, but has been ground with 114 degrees of lobe separation for the supercharger.

A complex but tasty sandwich
Speaking of which, the blower is effectively the meat in a sandwich which includes a suitably matched and modified Eddlebrock Torquer manifold underneath and a Madden OZNOS four-barrel kit plus Barry Grant 775 Gold Claw carbie on top.

The Madden kit comes complete with an adaptor plate and the NOS operates via the usual accelerator position switch once the master switch has been thrown.

Mark was actually still setting the nitrous up when we did the photos and was thinking of introducing a Hobbs pressure switch to activate the nitrous via boost control.

Whatever method of nitrous activation is used, the aim is to cool the fuel / air mixture before it enters the supercharger.

It’s worth mentioning here, that the 2100 R Whipple is a twin screw supercharger featuring Lysholm designed rotors. In plain English, that means it is a true air compressor and doesn’t just ‘blow’ additional air into the combustion chambers, like many of the superchargers we find on the market these days.

Because it is therefore compressing air, high boost pressures such as the planned maximum of 17psi in this application do generate temperatures on the discharge side of the supercharger which can be of concern.

Using nitrous like this to freeze the combustible mixture before it enters the blower is an effective way to combat excessive temperatures.

Simple? Not really…
The supercharger is motivated by a serpentine belt driven by a 200mm custom pulley at the crankshaft. The same pulley drives all the usual alternator, air conditioner etc via separate serpentine belts.

It sounds simple enough but took Mark a fair amount of calculating, especially in regards to achieving that 2 :1 ratio for the blower.

The main problem is that serpentine belts only come in fixed lengths, so one ‘close enough’ to what is required has to be used and then all the remaining calculations are based around this.

Unlike an EFI engine which needs plenty of sensors and the like telling the fuel system what to do at various boost levels, fuel delivery in this instance is fairly well self regulatory.

In other words, with the carbie properly set up, it automatically creates the correctly proportioned fuel mixture as the supercharger demands it.

Set up is important though, and that 14" diameter K & N air filter is capable of flowing 650Hp minimum.

The fuel system itself is impressive, consisting of a custom 16-gallon tank, Paxton Kamikaze EFI fuel pump, swirl pot and Holley pressure regulators.

The system is capable of delivering 1000Hp of fuel and maintains 8psi of fuel pressure as it enters the carbie. Jetting, on the other hand, is stock at the moment and Mark believes it will stay that way.

On the exhaust front, the Muffler Shop made up what can only be described as an exotic system for this Sandman.

The 1 7/8" extractors are a full 38" long each and lead into 2" piping, before an increase to 2 1/8" and ultimately a 3" twin system with X-piping and stainless mufflers courtesy of Geoff Garland.

By the time you read this, however, Group C side-exiting mufflers will be visible just in front of those rear tyres.

And of course, with supercharging, ignition control is vital.

Mark is using a Crane Fire Ball HI 6R arrangement in his Sandman, complete with a manually adjustable ignition retard module in the cabin.

Now for a quick confession - the 600Hp that we said this engine produces right at the top of the story, hasn’t actually been proven.

The previous build with supercharger and no nitrous produced a dyno proven 351 rear wheel ponies and Mark simply said that if the new motor with increased forced induction and nitrous doesn’t produce at least 600 Hp at the flywheel, he’ll be extremely disappointed.

We can certainly understand why !

To handle that sort of pressure, a 5-speed Tremec top loader from Dellows has been bolted under the floor pan and works alongside a balanced steel flywheel and heavy duty clutch from The Clutch Factory.

A 2-piece tailshaft from Berriman Engineering then feeds into that 4-pin Salisbury we mentioned earlier, complete with 4.44 ratio gears and LSD.

The one aspect to Mark’s Sandman that we haven’t discussed yet is the interior, although that’s academic really when you consider what the vehicle is all about.

Nonetheless, Mark finds the Recaro bucket seats and Momo Corse steering wheel enhance driver control when the party kicks in, while the obligatory 5" Autometer tacho and boost gauge provide adequate information.

In some ways it’s a pity that York has a reputation for older cars and middle aged gentlemen discussing the merits of vintage marques, because Mark’s activities certainly prove that the street performance scene is alive and well in ‘the bush’.